Preparation Method of Highly Active Co/SiO_2 Catalyst for Slurry Phase Fischer-Tropsch Synthesis

摘要

Cobalt catalysts were used since the 1930s in Fisher-Tropsch synthesis (FTS) for making liquid fuels from coal or natural gas. The characteristic features of cobalt catalysts are as follows: (1) low carbon dioxide yield, (II) high activity at low temperatures, (III) high paraffinic hydrocarbon yield with few oxygenates (1-4). Iglesia et al. (5) pointed out that hydrocarbon synthesis rates on cobalt catalyst were proportional of metal dispersion and independent of the metal oxide support (SiO_2, Al_2O_3, TiO_2 etc), while the C5~+ selectivity was slightly dependent on the dispersion of the support. Recent studies have shown that methanation turnover rates were also independent of cobalt dispersion on supported catalysts (6, 7) and of surface orientation on cobalt single crystals and films (6, 8). The catalyst activity can be predicted directly from cobalt dispersion values at typical FTS operation conditions (high pressure and CO high conversion).